Be aware of possible floods

Be aware of possible floods

By BRIAN KAJENGO

Those were there message sent to the people of South Africa by the Department of Water and Sanitation about the possible floods that might occur in the Country.

The Department emphasises  the country enters the critical period of high rainfall which could lead to flooding, the Department of Water and Sanitation (DWS), through the Hydrology unit, continues to monitor very closely the levels in all the rivers and dams in the country, with higher emphasis on the areas more prone to flooding.

Previous experience has helped sharpen the department’s vigilance and at the moment the department can report that there is no immediate threat of flooding anywhere in the country.

South Africa’s major river system which is vulnerable to flooding is the Orange - Vaal River system. This system cuts across four provinces, namely Gauteng, Free State, North West and Northern Cape. The major storage dams in the Vaal River are Grootdraai, Bloemhof and Vaal dams. Downstream of Vaal Dam there is Barrage in the Vereening area.

 This managed by Rand Water. The storage dams on the Orange River are Gariep and Vanderkloof dams.

The three dams in the Vaal River have gates which are controlled.  At this stage the dam level percentages are: Grootdraai-94, Vaal- 83 and Bloemhof-79. The storage dam level percentages on the Orange River are: Gariep -86 and Vanderkloof-95.

A particular reason that keeps the DWS on its toes at the moment is that the river catchments in most parts of the country are wet and should it continue to rain, the river levels for small tributaries will start to rise much quicker. 

The regions affected by isolated heavy rains for the past two days and thus vulnerable to localized floods are Gauteng, Mpumalanga and Limpopo.

In Gauteng, dams on the tributaries of the Vaal and Crocodile rivers are mainly NOT near spilling except for the Klerkskraal, Roodekopjes and Groot Marico dams, which are near 100% full. If these dams spill there will not be an immediate threat. This will depend on the duration of the spill over the dam.

Most of these rivers are not near bursting their banks. There is however isolated flooding likes the Hennops River in Centurion, due to high rainfall/flash flood in the city. The river accumulates more water for short durations which can last for three to six hours.

In Limpopo and Mpumalanga there are no small local dams spilling at the moment. The flows in the Olifants and Limpopo rivers monitored continually. These two rivers discharge into Mozambique. The Mozambique monitoring team continues to monitor the situation near real time. Should there be any strange readings, technicians sent out to the field to verify the information and communicate with the Mozambican authorities accordingly. These two rivers, Limpopo and Olifants, are also vulnerable to flooding, thus the keen eye trained on their levels.

Information also gathered for the Eastern Cape, KwaZulu Natal and the Northern Cape.